Diageo is closing its drinks packaging plant and 200-year-old distillery with the loss of 900 jobs.
The company said 700 jobs would go in Kilmarnock and another 150 jobs will go with the closure of the Port Dundas distillery, which has been producing whisky since 1810.
The jobs will be cut over two years with jobs in Ireland also under threat.
But the company said another 400 jobs would be created in Fife.
Diageo is the name behind brands including Guinness, Smirnoff vodka and Johnnie Walker whisky.
The company said its "long-term grain whisky requirements can be best met" at the group's Cameronbridge distillery in Fife, which is being expanded.
It hopes to transfer a number of axed positions to the Fife plant, which is being expanded under an £86m scheme.
Changes at its Shieldhall packaging plant in Glasgow will also lead to 30 job losses, Diageo said.
And the group is relocating around 80 office-based staff from Dundas House in Glasgow to another location in central Scotland over the next two years.
Outsourcing deals for its Hurlford consolidation warehouse in Ayrshire and Speyside haulage operation for distillery co-products are set to see 80 jobs transferred.
Scotland is one of Diageo's largest spirit supply centres, currently employing around 4,500 people and producing nearly 50 million cases of Scotch whisky and white spirits.